International Union for Nature Conservation (IUCN)

The Pacific islands of Oceania cover almost 15% of the world’s surface and are characterised by a high degree of ecosystem and species diversity. The region is characterised by thousands of isolated small coral atolls and higher volcanic islands, which has led to the high diversity of species found today. In fact, the number of plants and animals found nowhere else on earth (endemic species) is extremely high - often up to 90% for particular groups. Often, these rare and endemic species are adapted to specialised habitats and limited to small areas of a few islands.

The Pacific islands of Oceania cover almost 15% of the world’s surface and are characterised by a high degree of ecosystem and species diversity. The region is characterised by thousands of isolated small coral atolls and higher volcanic islands, which has led to the high diversity of species found today. In fact, the number of plants and animals found nowhere else on earth (endemic species) is extremely high - often up to 90% for particular groups. Often, these rare and endemic species are adapted to specialised habitats and limited to small areas of a few islands.

The Pacific islands of Oceania cover almost 15% of the world’s surface and are characterised by a high degree of ecosystem and species diversity. The region is characterised by thousands of isolated small coral atolls and higher volcanic islands, which has led to the high diversity of species found today. In fact, the number of plants and animals found nowhere else on earth (endemic species) is extremely high - often up to 90% for particular groups. Often, these rare and endemic species are adapted to specialised habitats and limited to small areas of a few islands.

The Pacific islands of Oceania cover almost 15% of the world’s surface and are characterised by a high degree of ecosystem and species diversity. The region is characterised by thousands of isolated small coral atolls and higher volcanic islands, which has led to the high diversity of species found today. In fact, the number of plants and animals found nowhere else on earth (endemic species) is extremely high - often up to 90% for particular groups. Often, these rare and endemic species are adapted to specialised habitats and limited to small areas of a few islands.

Invasive rodents have significant negative impacts on island biodiversity. All but the smallest of rodent eradications currently rely on island-wide rodenticide applications. Although significant advances have been made in mitigating unintended impacts, rodent eradication on inhabited islands remains extremely challenging. Current tools restrict eradication efforts to fewer than 15% of islands with critically endangered or endangered species threatened by invasive rodents.

Since 1999, the black rat (Rattus rattus) has been eradicated from 14 Italian islands, and eradication is ongoing on a further five islands. Most projects were funded by the European Union (EU) Life Programme. Over the years, eradication techniques have been improved and adapted to different situations, including aerial bait distribution on islands with large inaccessible areas, which otherwise would have relied on a manual bait distribution.

Sand Island, Midway Atoll National Wildlife Refuge (MANWR), is home to 21% of all nesting black-footed albatross (Phoebastria nigripes) and 47% of all nesting Laysan albatross (P. immutabilis) worldwide. During the 2015–2016 nesting season predation and disturbance by non-native house mice (Mus musculus), here documented for the first time, resulted in 70 abandoned nests, 42 adult birds killed and 480 wounded. In the following nesting season the affected area increased, resulting in 242 dead adults, 1,218 injured birds and 994 abandoned nests.

The Chagos Archipelago comprises some 58 islands covering 5,000 ha in the centre of the Indian Ocean. Black rats (Rattus rattus) were introduced about 230 years ago and have likely had a severe impact on the native terrestrial fauna, which is dominated by seabirds and land crabs. Most of the archipelago’s terrestrial land mass is vegetated with old coconut plantations, with over 75% of the native forest cleared for coconut from 26 of the largest islands.

The world is facing a biodiversity crisis. Nowhere is that more apparent than on oceanic islands where invasive species are a major threat for island biodiversity. Rats are one of the most detrimental of these and have been the target of numerous eradication programmes; a well-established conservation tool for island systems.